package com.ternnetwork.commons.utils;

import java.io.IOException;  
import java.lang.annotation.Annotation;
import java.util.ArrayList;
import java.util.HashSet;  
import java.util.LinkedList;  
import java.util.List;  
import java.util.Set;  
  
import org.apache.commons.logging.Log;  
import org.apache.commons.logging.LogFactory;  
import org.springframework.core.io.Resource;  
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;  
import org.springframework.core.io.support.ResourcePatternResolver;  
import org.springframework.core.type.classreading.CachingMetadataReaderFactory;  
import org.springframework.core.type.classreading.MetadataReader;  
import org.springframework.core.type.classreading.MetadataReaderFactory;  
import org.springframework.core.type.filter.AnnotationTypeFilter;  
import org.springframework.core.type.filter.TypeFilter;  
import org.springframework.util.ClassUtils;  
  
  
public class PackageClassesScaner {  
      
    protected final Log logger = LogFactory.getLog(getClass());  
      
    private static final String RESOURCE_PATTERN = "/**/*.class";  
      
    private ResourcePatternResolver resourcePatternResolver = new PathMatchingResourcePatternResolver();  
      
    private List<String> packagesList= new LinkedList<String>();  
      
    private List<TypeFilter> typeFilters = new LinkedList<TypeFilter>();  
      
    private Set<Class<?>> classSet= new HashSet<Class<?>>();  
      
    /** 
     * 构造函数 
     * @param packagesToScan 指定哪些包需要被扫描,支持多个包"package.a,package.b"并对每个包都会递归搜索 
     * @param annotationFilter 指定扫描包中含有特定注解标记的bean,支持多个注解 
     */  
    public PackageClassesScaner(String[] packagesToScan, Class<? extends Annotation>... annotationFilter){  
        if (packagesToScan != null) {  
            for (String packagePath : packagesToScan) {  
                this.packagesList.add(packagePath);  
            }  
        }  
        if (annotationFilter != null){  
            for (Class<? extends Annotation> annotation : annotationFilter) {  
                typeFilters.add(new AnnotationTypeFilter(annotation, false));  
            }  
        }  
    }  
      
    /** 
     * 将符合条件的Bean以Class集合的形式返回 
     * @return 
     * @throws IOException 
     * @throws ClassNotFoundException 
     */  
    public Set<Class<?>> getClassSet() throws IOException, ClassNotFoundException {  
        this.classSet.clear();  
        if (!this.packagesList.isEmpty()) {  
                for (String pkg : this.packagesList) {  
                    String pattern = ResourcePatternResolver.CLASSPATH_ALL_URL_PREFIX +  
                            ClassUtils.convertClassNameToResourcePath(pkg) + RESOURCE_PATTERN;  
                    Resource[] resources = this.resourcePatternResolver.getResources(pattern);  
                    MetadataReaderFactory readerFactory = new CachingMetadataReaderFactory(this.resourcePatternResolver);  
                    for (Resource resource : resources) {  
                        if (resource.isReadable()) {  
                            MetadataReader reader = readerFactory.getMetadataReader(resource);  
                            String className = reader.getClassMetadata().getClassName();  
                            if (matchesEntityTypeFilter(reader, readerFactory)) {  
                                this.classSet.add(Class.forName(className));  
                            }  
                        }  
                    }  
                }  
        }  
        //输出日志  
        if (logger.isInfoEnabled()){  
            for (Class<?> clazz : this.classSet) {  
                logger.info(String.format("Found class:%s", clazz.getName()));  
            }  
        }  
        return this.classSet;  
    }  
      
      
  
    /** 
     * 检查当前扫描到的Bean含有任何一个指定的注解标记 
     * @param reader 
     * @param readerFactory 
     * @return 
     * @throws IOException 
     */  
    private boolean matchesEntityTypeFilter(MetadataReader reader, MetadataReaderFactory readerFactory) throws IOException {  
        if (!this.typeFilters.isEmpty()) {  
            for (TypeFilter filter : this.typeFilters) {  
                if (filter.match(reader, readerFactory)) {  
                    return true;  
                }  
            }  
        }  
        return false;  
    }  
    
    public List<String> getClassesNameList(){
    	 List<String> retVal=new ArrayList<String>();
	    
		try {
			Set<Class<?>> set= getClassSet();
			for(Class cls:set){
				retVal.add(cls.getName());
			}
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
			return null;
		} catch (ClassNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
			return null;
		}
			return retVal;
			
    }
}